Crate android_build

Supports Android-specific Java build and run tasks in Rust projects from a Cargo build script.

Tools exposed by this crate

• javac: use the JavaBuild struct.
• java: use the JavaRun struct.
• d8: through the Dexer struct.

Environment variables in use

• ANDROID_HOME or ANDROID_SDK_ROOT: path to the Android SDK directory.
• ANDROID_BUILD_TOOLS_VERSION: the version of the Android build tools.
  • Examples: 33.0.1, 34.0.0-rc2.
  • This must be fully specified all in one string.
• ANDROID_PLATFORM, ANDROID_API_LEVEL, or ANDROID_SDK_VERSION: the platform version string (aka API level, SDK version) being targeted for compilation.
  • All three of these environment variables are treated identically.
  • Examples: 34, android-34, android-33, 33.
  • If an SDK extension must be specified, use the full string with the android prefix like so: android-33-ext4.
  • This may or may not include the SDK extension level as a suffix (see ANDROID_SDK_EXTENSION below).
• ANDROID_SDK_EXTENSION: the extension of the Android SDK.
  • To specify android-33-ext4, this can be set to -ext4, ext4, or just 4. All of these will be treated identically.
  • If ANDROID_PLATFORM/ANDROID_API_LEVEL/ANDROID_SDK_VERSION already includes an extension, then ANDROID_SDK_EXTENSION will be ignored.
• ANDROID_D8_JAR: the path to the d8.jar file.
• ANDROID_JAR: the path to the android.jar file.
• JAVA_HOME: the Java SDK directory.
• JAVA_SOURCE_VERSION: the Java version for source compatibility, which is passed to the --source javac option, e.g., 8 for Java 1.8, or 17 for Java 17.
• JAVA_TARGET_VERSION: the Java version for target compatibility, which is passed to the --target javac option, e.g., 7 for Java 1.7, or 17 for Java 17.

Acknowledgments

This crate simplifies some code found in other crates:

• dirs-sys for the Windows-specific home directory lookup.
• java-locator for finding the Java home directory on macOS, Linux, and Windows.
• jerk for arguments that can be passed into java and javac commands.
• i-slint-backend-android-activity for parsing javac version and finding the latest platform and build tools versions in the Android SDK installation.

Structs

DebugInfo

Debug information to include in the output of a javac build.

Dexer

A builder for generating Android DEX bytecode by invoking d8 commands.

JavaBuild

A builder for a javac command that can be invoked.

JavaRun

A builder for a java command that can be invoked.

Constants

ANDROID_API_LEVEL

ANDROID_BUILD_TOOLS_VERSION

ANDROID_D8_JAR

ANDROID_HOME

ANDROID_JAR

ANDROID_PLATFORM

ANDROID_SDK_EXTENSION

ANDROID_SDK_ROOT

ANDROID_SDK_VERSION

JAVA_HOME

JAVA_SOURCE_VERSION

JAVA_TARGET_VERSION

Traits

PathExt

An extension trait for checking if a path exists.

Functions

android_d8_jar

Returns the path to the d8.jar file for the given build tools version.

android_jar

Returns the path to the android.jar file for the given API level.

android_sdk

Returns the path to the Android SDK directory.

check_javac_version

Returns the major version number of the javac compiler.

java

Returns the path to the java executable by looking for $JAVA_HOME/bin/java.

java_home

Returns the JAVA_HOME path by attempting to discover it.

java_source_version

Returns the source version for compilation from environment variable JAVA_SOURCE_VERSION.

java_target_version

Returns the target version for compilation from environment variable JAVA_TARGET_VERSION.

javac

Returns the path to the javac compiler by looking for $JAVA_HOME/bin/javac.